Improvement in bit-stocks



H. L. PRATT.

Improvement in Bit-Stocks.

No.1131,829. Patented 061.1,1872.

p which is countersunk on its end at 0, so as to receive the smaller ends of the wed ge-shaped jaws D D, and which is made to traverse freely in the longitudinal groove in the socket, and this follower terminates in a screw, as

plainly shown in Figs. 1 and 5. B is a re- JUNrrED STATES IMPROVEMENT IN BlT-STOCKS.

Specification forming part of Letters Patent No. 131,829, dated October 1, 1872.

To all whom it may concern Be itk'nown that, I, HENRY L. PRATT, of

Brooklyn, in the county of Kings and State of New York, have invented certain Improvements in Bit-Stocks or Tool-Holders, of which the following is a specification;

Nature and Objects of theIiioeiitioii.

My said invention consists ina novel con:

.struction, combination, and arrangement of parts, which have for their object an efficient tool-holder, as fully hereinafter described.

Description of the Drawing.

In the sheet of drawing, Figure 1 is a longitudinal section taken along the line 2 2, cutting Figs. 2, 3, and 4; Fig. 2 is a transverse section through or m,- Fig. 3 is the same through General Description. A Arepresent the socket, which is provided with a slot of such shape as to receive and admit of a longitudinal movement a pair of wedge-shaped jaws, D D, and also may be provided with V-shaped grooves g g for a portion of its length, to receive the corners of the tang of thebit or tool. The jaws D D are provided with longitudinal grooves to take the corners of the tool, and they are pivoted together at the smaller ends by a pin, 0, and one of these jaws is countersunk, so that it will play freely upon the pin 0 and open for the tang of the tool, and their lower ends are made tapering, (see e,) as shown. Into the groove in the socket I insert a movable follower, G,

volving nut, which is in reality a part of the stock-crank, as shown by B, Fig. 6, and is, therefore, immovable in relation to it. This nut B has a plug cast thereon, which fits a corresponding cavity in the end of .the socket A, which plug has a groove, a, cut on its periphery to receive a retaining-pin, b, which holds it in position upon the socket A.

The operation of the tool-holder will be as follows: The operator will hold the socket A firmly in a vertical position with one hand, and with theother will turn the crank portion of the stock, which is, as before stated, rigidly attached to or a part of the nut B, and as the crank and nut are revolved in one direction the jaws D D will be driven by the follower forward, and, by reason of their wedge-shaped portion coming in contact with the inclined sides of the socket, (see d, Fig. 1,) they will close upon the tool and grasp it firmly, and, by turning the crank and nut in the reverse direction, the jaws will recede by gravity and open so that the tool can be readily removed. The jaws D D are automatically opened by means of their inclined ends, pivoted together, and resting in the cavity 0 in the follower G, and by gravity, the larger ends being the heaviest, whereby they readily fall into the longitudinal groove in the socket A.

Claims.

1. The combination of the longitudinallyslotted socket A with the sliding jaws D D, movable follower (J, and nut B, so that the jaws will be closed upon the tool by forcing 7 and specified.

HENRY L. PRATT. Witnesses:

E. P. STOUGHTON, O. A. DURG-IN- QFFICE. 

